Fibre Channel is an electrical interface standard used to interconnect devices physically. Various types of electrical connectors can be used in support of Fibre Channel. One type is a single connector attachment (SCA) connector. One SCA connector connects a Fibre Channel disk drive directly to a midplane or backplane of a storage enclosure and carries the command signaling, power input signals, and outputs required by the disk drive. Typically, the disk drive has a plug (male) SCA connector that mates with a receptacle (female) SCA connector on the midplane. The current version of SCA is SCA-2, and the SFF (Small Form Factor) Committee standard SFF-8451 governs the SCA-2 connector interface.
FIG. 1 shows a prior art receptacle SCA connector 10 about to mate with a plug SCA connector 12. At opposite ends of the receptacle SCA connector 10 are alignment guides 14-1, 14-2 (generally, 14). Each alignment guide 14 receives a respective alignment post 16-1, 16-2 when the plug and receptacle SCA connectors join. The alignment guides 12 facilitate blind mating, that is, a user can connect a disk drive to the midplane without needing to see either the plug or receptacle SCA connector.
The plug and receptacle SCA connectors each have a respective D-shaped housing 18, 20 with one or more rows of contacts (or pins) disposed therein (not shown). Normally, the housing 18 of the plug SCA connector closely receives the housing 20 of the receptacle SCA connector. Under certain conditions, however, the plug and receptacle SCA connectors will not mate, although all physical features of the plug and receptacle SCA connectors, and the delivery system (e.g., drive bay) that joins them, conform to the SCA-2 industry standard for SCA connectors. For example, when the angle of plugging a disk drive into a midplane slightly diverges from perpendicular relative to the midplane, the plug and receptacle SCA connectors can bind before their contacts regions are able to mate. More specifically, the housings 18, 20 of the plug and receptacle connectors may collide (at point 22) before the alignment guides 12 are able to align the plug SCA connector properly with respect to the receptacle SCA connector.